Purifying hydrocarbon oils



i To (ill whom it mag concern:

UNITED 2STATES PATIENT OFFICE.

CLARENCE I. ROBINSON, OF STATEN ISLAND, NEW -YORK, ASSIGNOR T0 STANDARD OIL COMPANY, OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW JERSEY.

- 1,387,868. No Drawing.

Be it known that I, CLARENCE I. ROBIN- SON, a citizen of the United States, residing at Staten Island, in the county of Richmond and State ofNew York, have invented a new and useful Improvement in Purifying I-Iydrocarbon Oils, of which the following is a specification.

The present invention relates to the further purification of petroleum oils or distillate which have been subjected to the action of sulfuric'acid for the removal of undesired constituents, and is, fully explained in the following specification. V

In the treatment of petroleum distillates, and particularly the lubricating fractions, for the manufacture of pale orwater-white products, the use of strong and of fuming sulfuric acid results in the formation of sul- -fonic acid compounds, some of which are is therefore impractical -to remove these sulfonic acids or soaps from the treated oils by the use of water or alkali solutions in the usual manner.

I have now discovered that iso-propyl alcohol and aqueous solutions thereof may be utilized for the removal of oil-dissolved sulfonated compounds, and that the solutions of the sulfonted compounds do not form emulsions with the oils and may be readily separated therefrom by settling. Although substantially pure iso-p'ropyl alcohol may be utilized for the purpose, ora concentrated iso-propyl alcohol containing approximately 92% of the alcohol, I findthat very satisfactory results are secured by the use :-of an aqueous solution ofiso-propyl alcohol containing 45% thereof (by volume).

The iso-propyl alcohol or solution thereof is added to the acid treated oils, which may have been treated with alkali for the neutralization of the acid,'and the mixture agitated.. The alcohol or alcohol solution is;

then permitted to settle out, carrying with Specification of Letters Patent.

Patented Aug. 16', 1921.

' Application filed March 18, 1920. Serial No. 365,617.

it the sulfonated compounds, and is removed from the oil, which may then be filtered Or otherwise prepared for the trade.

In illustration of the application of my invention, I may treat a steam distillate lubricating oil fraction of about 28 B., 385 F. flash and 215 viscosity (100 first with 5% of sulfuricacid of 66 Be, and subsequently with 37% of 20% fuming sulfuric acid, each'treatment being effected in several dumps, for the production of a water white oil for medicinal use. The treated oil is then treated with caustic soda solution for example, of 10% and is blown bright by forcing air through it. The treated oil contains a small amount of sodium salts of the sulfonated compounds of the oil '(1 to 2%, calculated as NaOH). It isnext treated with iso-propyl alcohol, for example by mixing it with 20% by volume of a 45% aqueoussolution of the alcohol. The mixture is thoroughly agitated, and is allowed to settle. During agitation and settling the oil is slightly warmed, for example, to 140 F. The alcohol, containing .the sulfonates in solution, is drawn ofi". Any alcohol remaining in the oil may be removed, fOIm example, by blowing air through the oil while the latter is slightly heated, for example, to 150 C, The oil may then be filtered, with clay, if desired, and is ready for'the market.

The alcohol solution, which contains the sulfonated compounds, may be treated for the recovery of the alcohol, for example, by

distillation.

In the above illustration the process of the present invention has been describedasapplied to an oil which has been subjected to a very heavy acid treatment. It is readily' apparent that it may also be applied to oils which have been subjected. to a less heavy treat, for example, to lubricating oils which have been treated only with. 66 B. sulfuric acid or to pale or white lubricating oils which have been treated with a less quantity of fuming acid than the medicinal oil above described. The process may likewise be applied to the direct removal of the sulfonic acids from the oil, without neutralization withalkali.

In the above illustration of the process the use of "appr'o'ximately 20% (by volume) of a 45% solution of propyl alcoholihas been described. Larger proportions or more con-v t erefrom, thereb centrated solutions of the alcoholor the pure alcohol itself may be used if desired, but I have found that in general there is not a substantial improvement in the results of the process. If substantially less ,than 20% of the propyl alcohol be used, safi 10 or 15%, Or if more dilute alcohol solutions are em-' I ployed'the removal of the sulfonated com pounds is not complete, andifreqnently considerable quantities of "oil are entrainedin the alcoholsolution. The iso-propyl alcohol may contain small amounts of h gher alco-g and o P without impairing its} uently. separating [the 4 iso-p'ropyl alcohol removing sulfonated compounds from t e oil. .j..-

,2. The. petroleum. oils which consists ifiaadmixin an aqueous solution of; iso-propylflaleoho therewith and subsequently separatin the iso-proply alcohol solntiofi'therefrom, t Vere .by removing; sulfonated. compounds the oil.

, petroleum oil distillates which consists in neutralizing-saiddistillates with alkali, then admixingiso-propyl alcohol therewith and subsequently separating the 51804 1 llalcohol therefrom, thereby removingfl'f' oiiated compounds from the oil.

petroleum oil ldi'stillates which consists in neutralizing said distillates withalkali, then the treated oil, v t a aqueous iso-propyl alcohol solution,"

permittlnglthe oil and alcohol soluti'o'nto- 75 o a 0 about 140 Rand withdrawing t e alcor n 'i 'hi'd i fonated .com-f f, a

process (if-purifying treated oils contaming dissolved su pounds which, consists in treating" the oil I i with iso-propyl alcohol, permitting the oil. process of purifying acid treated- 4;Tte a es of ses acid treated petroleum oil distillates which consists neutralizing said distillates with alkali, then -='-admixin iso-propylalcohol solution-therewith an subse uently separating the isopropyl alcohol-t erefrom, thereby. removing sulfonated; compounds fromthe oil.

-5. The-process of purifying acid treatedpetroleum ,oil distillafles ,wh1ch consists in neutralizing said distillates with alka1i,"then,-

a g 45% iso-propyl alcohol s olution therewit and subsequenflyseparatmg the iso-propyl alcohol therefrom, thereby removin sulfonated compounds from the oil. e processof purifying acid treated admixing 20% of 45% is -proplyl' alcohol solution. therewith and subsequen y separating the iso-pro yl alcohol therefrom, there-' blyi removing 's o fonated compounds from the The i process of preparinga refined hydro-carbon oil. which. consists-Pin; sub- 3 jecting a lubricating oil fraction" to successive treatment with concentrated an'dffumingsulfuric acid removing and. neutralizin admixing therewithj20% 0 se arate" while maintaining: a tem 'erature .hol solution.

8., The of and alcohol solution to separate thereby removing the sulfonated cgunp'ounds, and blowairthrough the treated oil while main-s.

nema: some i 

